With the widespread popularity of handsets, especially smart handsets, the security of the operating systems of the handsets becomes increasingly important. Currently, most smart handsets only use a login account and a password of a user as a means for identity authentication. However, this method is not secure, and as soon as the login account and the password are stolen by other users, all data on the operating system of the handset is exposed.
The technology using biological features of a human body, especially the face, for security authentication, develops rapidly. However, the computational complexity of the face authentication is high, and the computational resources of a handset are generally limited, so that it is difficult to support the face authentication with a heavy computational burden. In addition, in conventional face authentication systems, face authentication algorithms are rough and thus the probability of misjudgment is very high.